The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. Such scaling down has also increased the complexity of processing and manufacturing ICs.
Photolithography has been used for patterning a substrate (e.g., a wafer) in order to form various features of an IC. In a typical photolithography process, a resist layer is formed over a substrate and is exposed to a radiation to form latent images of an IC. Subsequently, it is developed in a developer (a chemical solution) to remove portions of the resist layer, thereby forming a resist pattern. The resist pattern is then used as an etch mask in subsequent etching processes, transferring the pattern to an underlying material layer. To be used as an etch mask, the resist pattern must exhibit certain etching resistance in the subsequent etching processes. Presently, there is a need for new and improved resist materials that provide increased etching resistance over existing resist materials.